2 * ACPI PCI Hot Plug IBM Extension
4 * Copyright (C) 2004 Vernon Mauery <vernux@us.ibm.com>
5 * Copyright (C) 2004 IBM Corp.
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or (at
12 * your option) any later version.
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
17 * NON INFRINGEMENT. See the GNU General Public License for more
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 * Send feedback to <vernux@us.ibm.com>
28 #include <linux/init.h>
29 #include <linux/module.h>
30 #include <linux/kernel.h>
31 #include <acpi/acpi_bus.h>
32 #include <linux/sysfs.h>
33 #include <linux/kobject.h>
34 #include <asm/uaccess.h>
35 #include <linux/moduleparam.h>
38 #include "pci_hotplug.h"
40 #define DRIVER_VERSION "1.0.1"
41 #define DRIVER_AUTHOR "Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>"
42 #define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver IBM extension"
46 MODULE_AUTHOR(DRIVER_AUTHOR);
47 MODULE_DESCRIPTION(DRIVER_DESC);
48 MODULE_LICENSE("GPL");
49 MODULE_VERSION(DRIVER_VERSION);
50 module_param(debug, bool, 0644);
51 MODULE_PARM_DESC(debug, " Debugging mode enabled or not");
52 #define MY_NAME "acpiphp_ibm"
55 #define dbg(format, arg...) \
58 printk(KERN_DEBUG "%s: " format, \
62 #define FOUND_APCI 0x61504349
63 /* these are the names for the IBM ACPI pseudo-device */
64 #define IBM_HARDWARE_ID1 "IBM37D0"
65 #define IBM_HARDWARE_ID2 "IBM37D4"
67 #define hpslot_to_sun(A) (((struct slot *)((A)->private))->acpi_slot->sun)
69 /* union apci_descriptor - allows access to the
70 * various device descriptors that are embedded in the
73 union apci_descriptor {
97 /* struct notification - keeps info about the device
98 * that cause the ACPI notification event
100 struct notification {
101 struct acpi_device *device;
105 static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status);
106 static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status);
107 static void ibm_handle_events(acpi_handle handle, u32 event, void *context);
108 static int ibm_get_table_from_acpi(char **bufp);
109 static ssize_t ibm_read_apci_table(struct kobject *kobj,
110 char *buffer, loff_t pos, size_t size);
111 static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
112 u32 lvl, void *context, void **rv);
113 static int __init ibm_acpiphp_init(void);
114 static void __exit ibm_acpiphp_exit(void);
116 static acpi_handle ibm_acpi_handle;
117 static struct notification ibm_note;
118 static struct bin_attribute ibm_apci_table_attr = {
120 .name = "apci_table",
121 .owner = THIS_MODULE,
124 .read = ibm_read_apci_table,
127 static struct acpiphp_attention_info ibm_attention_info =
129 .set_attn = ibm_set_attention_status,
130 .get_attn = ibm_get_attention_status,
131 .owner = THIS_MODULE,
135 * ibm_slot_from_id - workaround for bad ibm hardware
136 * @id: the slot number that linux refers to the slot by
138 * Description: this method returns the aCPI slot descriptor
139 * corresponding to the Linux slot number. This descriptor
140 * has info about the aPCI slot id and attention status.
141 * This descriptor must be freed using kfree when done.
143 static union apci_descriptor *ibm_slot_from_id(int id)
146 union apci_descriptor *ret = NULL, *des;
149 size = ibm_get_table_from_acpi(&table);
150 des = (union apci_descriptor *)table;
151 if (memcmp(des->header.sig, "aPCI", 4) != 0)
154 des = (union apci_descriptor *)&table[ind += des->header.len];
155 while (ind < size && (des->generic.type != 0x82 ||
156 des->slot.slot_num != id)) {
157 des = (union apci_descriptor *)&table[ind += des->generic.len];
160 if (ind < size && des->slot.slot_num == id)
165 ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL);
166 memcpy(ret, des, sizeof(union apci_descriptor));
173 * ibm_set_attention_status - callback method to set the attention LED
174 * @slot: the hotplug_slot to work with
175 * @status: what to set the LED to (0 or 1)
177 * Description: this method is registered with the acpiphp module as a
178 * callback to do the device specific task of setting the LED status
180 static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status)
182 union acpi_object args[2];
183 struct acpi_object_list params = { .pointer = args, .count = 2 };
186 union apci_descriptor *ibm_slot;
188 ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));
190 dbg("%s: set slot %d (%d) attention status to %d\n", __FUNCTION__,
191 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
194 args[0].type = ACPI_TYPE_INTEGER;
195 args[0].integer.value = ibm_slot->slot.slot_id;
196 args[1].type = ACPI_TYPE_INTEGER;
197 args[1].integer.value = (status) ? 1 : 0;
201 stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", ¶ms, &rc);
202 if (ACPI_FAILURE(stat)) {
203 err("APLS evaluation failed: 0x%08x\n", stat);
206 err("APLS method failed: 0x%08lx\n", rc);
213 * ibm_get_attention_status - callback method to get attention LED status
214 * @slot: the hotplug_slot to work with
215 * @status: returns what the LED is set to (0 or 1)
217 * Description: this method is registered with the acpiphp module as a
218 * callback to do the device specific task of getting the LED status
220 * Because there is no direct method of getting the LED status directly
221 * from an ACPI call, we read the aPCI table and parse out our
222 * slot descriptor to read the status from that.
224 static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status)
226 union apci_descriptor *ibm_slot;
228 ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));
230 if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08)
235 dbg("%s: get slot %d (%d) attention status is %d\n", __FUNCTION__,
236 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
244 * ibm_handle_events - listens for ACPI events for the IBM37D0 device
245 * @handle: an ACPI handle to the device that caused the event
246 * @event: the event info (device specific)
247 * @context: passed context (our notification struct)
249 * Description: this method is registered as a callback with the ACPI
250 * subsystem it is called when this device has an event to notify the OS of
252 * The events actually come from the device as two events that get
253 * synthesized into one event with data by this function. The event
254 * ID comes first and then the slot number that caused it. We report
255 * this as one event to the OS.
257 * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will
258 * only re-enable the interrupt that causes this event AFTER this method
259 * has returned, thereby enforcing serial access for the notification struct.
261 static void ibm_handle_events(acpi_handle handle, u32 event, void *context)
263 u8 detail = event & 0x0f;
264 u8 subevent = event & 0xf0;
265 struct notification *note = context;
267 dbg("%s: Received notification %02x\n", __FUNCTION__, event);
269 if (subevent == 0x80) {
270 dbg("%s: generationg bus event\n", __FUNCTION__);
271 acpi_bus_generate_event(note->device, note->event, detail);
277 * ibm_get_table_from_acpi - reads the APLS buffer from ACPI
278 * @bufp: address to pointer to allocate for the table
280 * Description: this method reads the APLS buffer in from ACPI and
281 * stores the "stripped" table into a single buffer
282 * it allocates and passes the address back in bufp
284 * If NULL is passed in as buffer, this method only calculates
285 * the size of the table and returns that without filling
288 * returns < 0 on error or the size of the table on success
290 static int ibm_get_table_from_acpi(char **bufp)
292 union acpi_object *package;
293 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
298 status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer);
299 if (ACPI_FAILURE(status)) {
300 err("%s: APCI evaluation failed\n", __FUNCTION__);
304 package = (union acpi_object *) buffer.pointer;
306 (package->type != ACPI_TYPE_PACKAGE) ||
307 !(package->package.elements)) {
308 err("%s: Invalid APCI object\n", __FUNCTION__);
309 goto read_table_done;
312 for(size = 0, i = 0; i < package->package.count; i++) {
313 if (package->package.elements[i].type != ACPI_TYPE_BUFFER) {
314 err("%s: Invalid APCI element %d\n", __FUNCTION__, i);
315 goto read_table_done;
317 size += package->package.elements[i].buffer.length;
321 goto read_table_done;
323 lbuf = kmalloc(size, GFP_KERNEL);
324 dbg("%s: element count: %i, ASL table size: %i, &table = 0x%p\n",
325 __FUNCTION__, package->package.count, size, lbuf);
329 memset(lbuf, 0, size);
332 goto read_table_done;
336 for (i=0; i<package->package.count; i++) {
338 package->package.elements[i].buffer.pointer,
339 package->package.elements[i].buffer.length);
340 size += package->package.elements[i].buffer.length;
344 kfree(buffer.pointer);
349 * ibm_read_apci_table - callback for the sysfs apci_table file
350 * @kobj: the kobject this binary attribute is a part of
351 * @buffer: the kernel space buffer to fill
352 * @pos: the offset into the file
353 * @size: the number of bytes requested
355 * Description: gets registered with sysfs as the reader callback
356 * to be executed when /sys/bus/pci/slots/apci_table gets read
358 * Since we don't get notified on open and close for this file,
359 * things get really tricky here...
360 * our solution is to only allow reading the table in all at once
362 static ssize_t ibm_read_apci_table(struct kobject *kobj,
363 char *buffer, loff_t pos, size_t size)
365 int bytes_read = -EINVAL;
368 dbg("%s: pos = %d, size = %zd\n", __FUNCTION__, (int)pos, size);
371 bytes_read = ibm_get_table_from_acpi(&table);
372 if (bytes_read > 0 && bytes_read <= size)
373 memcpy(buffer, table, bytes_read);
380 * ibm_find_acpi_device - callback to find our ACPI device
381 * @handle: the ACPI handle of the device we are inspecting
382 * @lvl: depth into the namespace tree
383 * @context: a pointer to our handle to fill when we find the device
384 * @rv: a return value to fill if desired
386 * Description: used as a callback when calling acpi_walk_namespace
387 * to find our device. When this method returns non-zero
388 * acpi_walk_namespace quits its search and returns our value
390 static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
391 u32 lvl, void *context, void **rv)
393 acpi_handle *phandle = (acpi_handle *)context;
395 struct acpi_device_info info;
396 struct acpi_buffer info_buffer = {
397 .length = sizeof(struct acpi_device_info),
401 status = acpi_get_object_info(handle, &info_buffer);
402 if (ACPI_FAILURE(status)) {
403 err("%s: Failed to get device information", __FUNCTION__);
406 info.hardware_id.value[sizeof(info.hardware_id.value) - 1] = '\0';
408 if (info.current_status && (info.valid & ACPI_VALID_HID) &&
409 (!strcmp(info.hardware_id.value, IBM_HARDWARE_ID1) ||
410 !strcmp(info.hardware_id.value, IBM_HARDWARE_ID2))) {
411 dbg("found hardware: %s, handle: %p\n", info.hardware_id.value,
414 /* returning non-zero causes the search to stop
415 * and returns this value to the caller of
416 * acpi_walk_namespace, but it also causes some warnings
417 * in the acpi debug code to print...
424 static int __init ibm_acpiphp_init(void)
428 struct acpi_device *device;
429 struct kobject *sysdir = &pci_hotplug_slots_subsys.kset.kobj;
431 dbg("%s\n", __FUNCTION__);
433 if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
434 ACPI_UINT32_MAX, ibm_find_acpi_device,
435 &ibm_acpi_handle, NULL) != FOUND_APCI) {
436 err("%s: acpi_walk_namespace failed\n", __FUNCTION__);
440 dbg("%s: found IBM aPCI device\n", __FUNCTION__);
441 if (acpi_bus_get_device(ibm_acpi_handle, &device)) {
442 err("%s: acpi_bus_get_device failed\n", __FUNCTION__);
446 if (acpiphp_register_attention(&ibm_attention_info)) {
451 ibm_note.device = device;
452 status = acpi_install_notify_handler(ibm_acpi_handle,
453 ACPI_DEVICE_NOTIFY, ibm_handle_events,
455 if (ACPI_FAILURE(status)) {
456 err("%s: Failed to register notification handler\n",
462 ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL);
463 retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr);
468 acpiphp_unregister_attention(&ibm_attention_info);
473 static void __exit ibm_acpiphp_exit(void)
476 struct kobject *sysdir = &pci_hotplug_slots_subsys.kset.kobj;
478 dbg("%s\n", __FUNCTION__);
480 if (acpiphp_unregister_attention(&ibm_attention_info))
481 err("%s: attention info deregistration failed", __FUNCTION__);
483 status = acpi_remove_notify_handler(
487 if (ACPI_FAILURE(status))
488 err("%s: Notification handler removal failed\n", __FUNCTION__);
489 /* remove the /sys entries */
490 sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr);
493 module_init(ibm_acpiphp_init);
494 module_exit(ibm_acpiphp_exit);